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Typical operating characteristics (continued) – Rainbow Electronics MAX799 User Manual

Page 7

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MAX796/MAX797/MAX799

Step-Down Controllers with

Synchronous Rectifier for CPU Power

_______________________________________________________________________________________

7

____________________________Typical Operating Characteristics (continued)

(T

A

= +25°C, unless otherwise noted.)

0

200

µ

400

µ

600

µ

800

µ

14m

15m

16m

0

4

8

12

16

20

24

28

32

QUIESCENT SUPPLY CURRENT

vs. SUPPLY VOLTAGE,

5V/3A CIRCUIT IN IDLE MODE

MAX796-04

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (A)

STANDARD MAX797 APPLICATION
CONFIGURED FOR 5V
SKIP = LOW
SYNC = REF

0

0.2

0.4

0.6

0.8

1.2

1.0

1.4

1.6

0

4

8

12

16

20

24

28

32

SHUTDOWN SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX796-07

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (

µ

A)

DEVICE CURRENT ONLY
SHDN = LOW

0

200

400

600

800

1200

1000

1400

0

4

8

12

16

20

24

28

32

MAX796-05

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (

µ

A)

QUIESCENT SUPPLY CURRENT

vs. SUPPLY VOLTAGE,

3.3V/3A CIRCUIT IN IDLE MODE

STANDARD MAX797 3.3V/3A
CIRCUIT, FIGURE 1
SKIP = LOW
SYNC = REF

SWITCHING

NOT SWITCHING
(FB FORCED TO 3.5V)

0

10

20

30

0

4

8

12

16

20

24

28

32

MAX796-06

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

QUIESCENT SUPPLY CURRENT vs.

SUPPLY VOLTAGE, LOW-NOISE MODE

f = 150kHz

f = 300kHz

STANDARD MAX797 3.3V/3A
CIRCUIT, FIGURE 1
SKIP = HIGH

0

0.01

1

10

0.1

DROPOUT VOLTAGE vs.

LOAD CURRENT

200

100

300

400

500

600

700

800

MAX796-08

LOAD CURRENT (A)

V

IN

- V

OUT

(mV)

STANDARD MAX797 APPLICATION
CONFIGURED FOR 5V
V

OUT

> 4.8V

f = 150kHz

f = 300kHz

0

1

100

1000

10

REF LOAD-REGULATION ERROR

vs. LOAD CURRENT

5

10

15

20

MAX796-09

REF LOAD CURRENT (

µ

A)

LOAD REGULATION

V (mV)

0

200

100

300

400

500

0

20

40

60

80

MAX796-10

VL LOAD CURRENT (mA)

LOAD REGULATION

V (mV)

VL LOAD-REGULATION ERROR

vs. LOAD CURRENT

0

50

100

150

200

250

300

350

400

450

0

4

8

12

16

20

24

28

32

MAX796-11

SUPPLY VOLTAGE (V)

MAXIMUM SECONDARY CURRENT (mA)

MAX796

MAXIMUM SECONDARY CURRENT

vs. SUPPLY VOLTAGE, 5V/15V CIRCUIT

I

OUT

(MAIN) = 0A

I

OUT

(MAIN) = 3A

CIRCUIT OF FIGURE 11
TRANSFORMER = TTI5870
V

SEC

> 12.75V

1000

0.1

100

µ

10m

1

SWITCHING FREQUENCY vs.

LOAD CURRENT

10

LOAD CURRENT (A)

SWITCHING FREQUENCY (kHz)

100

1m

100m

SYNC = REF (300kHz)
SKIP = LOW

+5V, V

IN

= 7.5V

1

+5V, V

IN

= 30V

+3.3V, V

IN

= 7.5V